Though I could not find anything from the DFG or FGC, it appears that the USFW Service made an interesting finding in late 2004:
http://www.fws.gov/policy/library/04-21800.html
Here are some of the more pertainant points:
"SUMMARY: We, the U.S. Fish and Wildlife Service (Service), announce a
90-day finding for a petition to list the western gray squirrel
(Sciurus griseus) as endangered under the Endangered Species Act of
1973, as amended. We find the petition does not present substantial
scientific or commercial information indicating that listing this
species may be warranted.
DATES: The finding announced in this document was made on September 29,
2004."
"CDFG concludes that hunting mortality does not
adversely affect western gray squirrel populations (CDFG 2002). Hunting
for tree squirrels is permitted within the range of Sciurus griseus
griseus and S. g. nigripes, but is not permitted in southern California
within most of the range of S. g. anthonyi. There are no data showing
populations of the western gray squirrel having declined such that the
subspecies may be threatened or endangered in California. The National
Heritage Status Rank for the western gray squirrel in California is S4
(Apparently Secure) and S5 (Secure) (NatureServe Explorer 2002)."
"We reviewed the best available information on the status of the
western gray squirrel THROUGHOUT its range, including information in
the petition and from other sources. We do not find there is a threat
that constitutes an emergency posing significant risk to the well-being
of the western gray squirrel across all or a significant portion of the
species' range as discussed above. Western gray squirrel populations
are apparently secure in California and Nevada."
It appears that the failure of that particular petition opens the field for ours. USFWS has already done half the footwork.
